Sizing tolerances.

[WelshShooter]

It's easy to see why people would accidentally call the bullet a head, if you stood a cartridge upright the bullet is at the top and would look like the "head". This is wrong, it's the bottom of the case which is the head because the calibre and case brand is stamped on this part of the case and is called the "headstamp." It doesn't help that many major outlets still refer to bullets as heads.

To answer your question the case lengths provided in literature are maximum case lengths which should not be exceeded otherwise your ammunition may not chamber in your rifle. I have an LE Wilson case trimmer and they reccomend to trim 0.010" below maximum case length, therefore in your case the 308win cases would be trimmed back to 2.005".

Your cases which measure at 2.008" are acceptable.

Source, LE Wilson trim length table
http://www.lewilson.com/images/THE_WILS ... RIMMER.pdf

[ruger_steve]

It's easy to see why people would accidentally call the bullet a head, if you stood a cartridge upright the bullet is at the top and would look like the "head". This is wrong, it's the bottom of the case which is the head because the calibre and case brand is stamped on this part of the case and is called the "headstamp." It doesn't help that many major outlets still refer to bullets as heads.

To answer your question the case lengths provided in literature are maximum case lengths which should not be exceeded otherwise your ammunition may not chamber in your rifle. I have an LE Wilson case trimmer and they reccomend to trim 0.010" below maximum case length, therefore in your case the 308win cases would be trimmed back to 2.005".

Your cases which measure at 2.008" are acceptable.

Source, LE Wilson trim length table
http://www.lewilson.com/images/THE_WILS ... RIMMER.pdf

Brilliant. Puts my mind at rest. Thanks for your answer.


Sent from my boing using "An application"

[ruger_steve]

Your cases which measure at 2.008" are acceptable.

Source, LE Wilson trim length table
http://www.lewilson.com/images/THE_WILS ... RIMMER.pdf

One more thing, (and I’m sure it will be covered in the book when I finally finish reading it all) but the dimensions of the final overall length with the bullet in that’s stated in the book, is that going to be proportionate to the casing? Ie if the casing is 0.010 shorter than in the book, is the overall length going to be 0.010 shorter than in the book also?

Please note that I AM NOT going to be trying any of this until I am certain I know what I need to know. This is still early days. All I have done is de-primed and tumbled my used brass but have stopped there until I know what I’m doing.

[Mattnall]

Your cases which measure at 2.008" are acceptable.

Source, LE Wilson trim length table
http://www.lewilson.com/images/THE_WILS ... RIMMER.pdf

One more thing, (and I’m sure it will be covered in the book when I finally finish reading it all) but the dimensions of the final overall length with the bullet in that’s stated in the book, is that going to be proportionate to the casing? Ie if the casing is 0.010 shorter than in the book, is the overall length going to be 0.010 shorter than in the book also?

That will all depend upon your bullet choice and chamber. Not all bullets are the same length and even some from the same batch/box of bullets will differ by a few thou' so measuring to the ogive is better than overall length, but then you most likely won't know what that measurement is from the manual. Use the manual as a guide but don't sweat too much about the last 0.001" or so, that can come once you decide you need to tweek your loads to give that extra bit of consistency.
Some shooters load bullets longer or shorter to better fit their chamber requirements and other needs. This is best done after you gain some experience with your reloads and understand the signs of over pressure etc.

However, generally if you, for instance, have a tried and tested round and then make the case a few thou' shorter the bullet can stay where it is (keeping the round the same length as before) as long as it is still securely held by the neck. Pushing the bullet in further would reduce the cartridge volume and may need an adjustment on powder charge as the pressure may also change as a result.

[1066]

Also depends very much if you plan to single feed or feed from the magazine - SAAMI spec length OAL will fit in your magazine - best accuracy length may not.

[ovenpaa]

Yes, even places like Kranks refer to the bullet as a head however it is still wrong. I just did a quick search for a drawing illustrating a loaded rounds and naming the different parts and was amazed at just how many inaccurate images there are on the internet. Even this one is not great and is incomplete.

[ovenpaa]

Slightly better:

[ruger_steve]

Slightly better:

cartdraw.jpg

brilliant. Thanks for that. The guy I bought it from have me some of the rounds he made from the kit I now have so will probably copy them at first as I know they work. Then as you say tweet them when I know a little more.


Sent from my boing using "An application"

[ovenpaa]

Well ignore the crimps and belt as they tend to not apply to many of the things we shoot these days :)

I really should sit down and draw something that truly covers all of the components of the loaded round including the meplat and ogive as they are important items to understand for both optimising chamber fit and as references for measuring and batching bullets for some shooting disciplines and some competition use.

I feel an hour or so of CAD working calling me :)

[FredB]

The shop wants your custom: notes that you are new to the game and ignorant and sends you bullets. I have been reloading for more than 40 years and never heard the term "bullet head" until faily recently.
Fred